Final boss should be the biggest disadvantage that might destroy Bitcoin.
Is it scalability?
High fees will encourage the price to rise, so not something need to be worried.
Is it regulatory pressure?
It's 50/50, but people can still use Bitcoin without permission by government, so there's a way to get out.
Is it energy debates?
There are few alternatives to generate renewable energy.
Or is it simply time and adoption?
It's not a problem.
I think the final boss would be centralization, we're getting closer to that. Mining are more centralized since many small miners get away, the coins are more centralized because centralized institutions e.g. ETFs, government including centralized exchanges hold Bitcoin.
Unfortunately most people not aware with that.